检索结果-南通市图书馆

Lactate as a regulator of iron homeostasis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Life Metabolism 2023年第5期2卷 8-11页

作者： gregory j.anderson David M.Frazer Iron Metabolism Laboratory QIMR Berghofer Medical Research InstituteBrisbaneQueensland 4006Australia Molecular Nutrition Laboratory QIMR Berghofer Medical Research InstituteBrisbaneQueensland 4006Australia

The key metabolic intermediate lactate can increase expression of the liver-derived peptide hepcidin,the central regulator of body iron homeostasis.A new paper by Liu et *** that lactate achieves this by binding to and activating soluble adenylyl cyclase,thereby increasing cellular cyclic adenosine monophosphate(cAMP)and enhancing signaling through the bone morphogenetic protein(BMP)pathway to modulate hepcidin expression.

关键词： expression thereby homeostasis

Global weirding at mass extinction horizons

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第1期11卷 10-12页

作者： gregory j.Retallack Department of Earth Sciences University of Oregon

A strong motivation for studying mass extinctions is understanding how current climatic and biodiversity crises will affect creatures living on land such as ourselves. Perhaps the question is: how bad can it get? In that case, terrestrial Permian-Triassic mass extinctions are an irresistible worst-case scenario [1].

关键词：

Opposite latitudinal gradients for species richness and phylogenetic diversity of endemic snakes in the Atlantic Forest

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2024年第4期70卷 522-530页

作者： joséThales da Motta Portillo josuéanderson Rēgo Azevedo Fausto Erritto Barbo Ricardo j.Sawaya Programa de Pos-Graduacao em Biologia Animal Instituto de BiocienciasLetras e Ciencias ExatasUniversidade Estadual Paulista"Julio de Mesquita Filho"Rua Cristovao Colombo2265Sao Josédo Rio PretoSao Paulo 15054-000Brazil Programa de Colecoes Cientificas Biologicas Coordenagao de BiodiversidadeInstituto Nacional de Pesquisas da AmazoniaAvenida AndréAraujo2936ManausAmazonas 69067-375Brazil Gothenburg Global Biodiversity Centre University of GothenburgBox 461GothenburgVastra Gotaland SE-40530Sweden Instituto Federal de Educacao Ciencia e Tecnologia de Minas GeraisRodovia Machado-Paraguacukm 3MachadoMinas Gerais 37750-000Rraizil Centro de Ciencias Naturais e Humanas UniversidadeFederaldo ABCRua Arcturus03Sao Bernardo do CampoSao Paulo09606-070Brazil

The decrease in species richness toward higher latitudes is an expected biogeographical *** pattern could be related to particular envi-ronmental constraints and the evolutionary history of ***,species richness does not fully represent the evolutionary history of the clades behind their *** diversity better clarifies the role of historical factors in biogeographical *** analyzed envi-ronmental and historical drivers related to latitudinal variation in species richness and phylogenetic diversity of Atlantic Forest endemic *** implemented species distribution models,from voucherbased locality points,to map the snake ranges and *** used generalized additive mixed models to evaluate the relationships among the diversity metrics and area,topographical roughness,and past climate change velocity since the Last Maximum Glacial in the Atlantic Forest latitudinal *** to the expected general pattern,species richness was higher toward higher latitudes,being positively related to past climatic *** richness also increased with total area and higher topographical *** diversity,on the other hand,showed opposite relationships related to the same *** diversity increased with lower climatic stability in lower ***,dimensions of diversity were affected in different ways by historical and environmental constraints in this unique and threatened biodiversity hotspot.

关键词： biodiversity latitudinal gradient neotropical region phylogenetic diversity serpents species richness.

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

一颗自由进动的磁星

科学通报 2024年第25期69卷 3675-3677页

作者：高勇 gregory Desvignes 邵立晶 Max Planck Institute for Gravitational Physics (Albert Einstein Institute) Max Planck Institute for Radio Astronomy 北京大学科维理天文与天体物理研究所中国科学院国家天文台

磁星是一类具有强磁场和长自转周期的年轻中子星.这些天体极其致密,半径约为12 km,但质量却可达太阳的1～2倍.在已知的30颗磁星中,只有少数会偶尔产生射电辐射.磁星转动时,射电束像灯塔一样扫过天空,天文学家正是从这些规律的脉冲信号... 详细信息

磁星是一类具有强磁场和长自转周期的年轻中子星.这些天体极其致密,半径约为12 km,但质量却可达太阳的1～2倍.在已知的30颗磁星中,只有少数会偶尔产生射电辐射.磁星转动时,射电束像灯塔一样扫过天空,天文学家正是从这些规律的脉冲信号中探索中子星的奥秘. 2018年末,磁星XTE j1810-197在经历了X射线爆发后再次产生射电辐射,结束了其长达十年的射电静默期.通过长时间、高频次的监测,我们在射电偏振信号中发现射电束相对于地球的倾角发生了显著变化,并且这种变化在几个月内逐渐消失[1].我们认为这种变化是由磁星的自由进动引起的,并提出了衰减的进动模型来解释这一观测现象.这一发现不仅帮助我们更深入地理解了磁星的内部结构和辐射几何,而且很可能排除了自由进动作为重复快速射电暴起源的理论模型.

关键词：射电辐射磁星中子星 X射线爆发脉冲信号强磁场理论模型高频次

同方期刊数据库

Integrins and their potential roles in mammalian pregnancy

在线全文

学校读者我要写书评

暂无评论

journal of Animal Science and Biotechnology 2024年第1期15卷 1-19页

作者： gregory A.johnson Robert C.Burghardt Fuller W.Bazer Heewon Seo joe W.Cain Department of Veterinary Integrative Biosciences School of Veterinary Medicine and Biomedical SciencesTexas A&M UniversityCollege StationTX 77843‑4459USA Department of Animal Science College of Agriculture and Life SciencesTexas A&M UniversityCollege StationTX 77843‑2471USA

Integrins are a highly complex family of receptors that, when expressed on the surface of cells, can mediate reciprocal cell-to-cell and cell-to-extracellular matrix(ECM) interactions leading to assembly of integrin adhesion complexes(IACs) that initiate many signaling functions both at the membrane and deeper within the cytoplasm to coordinate processes including cell adhesion, migration, proliferation, survival, differentiation, and metabolism. All metazoan organisms possess integrins, and it is generally agreed that integrins were associated with the evolution of multicellularity, being essential for the association of cells with their neighbors and surroundings, during embryonic development and many aspects of cellular and molecular biology. Integrins have important roles in many aspects of embryonic development, normal physiology, and disease processes with a multitude of functions discovered and elucidated for integrins that directly influence many areas of biology and medicine, including mammalian pregnancy, in particular implantation of the blastocyst to the uterine wall, subsequent placentation and conceptus(embryo/fetus and associated placental membranes) development. This review provides a succinct overview of integrin structure, ligand binding, and signaling followed with a concise overview of embryonic development, implantation, and early placentation in pigs, sheep, humans, and mice as an example for rodents. A brief timeline of the initial localization of integrin subunits to the uterine luminal epithelium(LE) and conceptus trophoblast is then presented, followed by sequential summaries of integrin expression and function during gestation in pigs, sheep, humans, and rodents. As appropriate for this journal, summaries of integrin expression and function during gestation in pigs and sheep are in depth, whereas summaries for humans and rodents are brief. Because similar models to those illustrated in Fig. 1, 2, 3, 4, 5 and 6 are present throughout the sc

关键词： Humans Implantation Integrins Pigs Pregnancy Rodents Sheep

A functional tacrolimus-releasing nerve wrap for enhancing nerve regeneration following surgical nerve repair

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第1期20卷 291-304页

作者： Simeon C.Daeschler Katelyn j.W.So Konstantin Feinberg Marina Manoraj jenny Cheung jennifer Zhang Kaveh Mirmoeini jPaul Santerre Tessa Gordon gregory HBorschel SickKids Research Institute Neuroscience and Mental Health ProgramTorontoONCanada Institute of Biomaterials and Biomedical Engineering University of TorontoTorontoONCanada Indiana University School of Medicine IndianapolisINUSA Division of Plastic and Reconstructive Surgery the Hospital for Sick ChildrenTorontoONCanada Translational Biology and Engineering Program Ted Rogers Centre for Heart ResearchInstitute of Biomedical EngineeringFaculty of DentistryUniversity of TorontoTorontoONCanada

Axonal regeneration following surgical nerve repair is slow and often incomplete,resulting in poor functional recovery which sometimes contributes to lifelong ***,there are no FDA-approved therapies available to promote nerve *** accelerates axonal regeneration,but systemic side effects presently outweigh its potential benefits for peripheral nerve *** authors describe herein a biodegradable polyurethane-based drug delivery system for the sustained local release of tacrolimus at the nerve repair site,with suitable properties for scalable production and clinical application,aiming to promote nerve regeneration and functional recovery with minimal systemic drug *** is encapsulated into co-axially electrospun polycarbonate-urethane nanofibers to generate an implantable nerve wrap that releases therapeutic doses of bioactive tacrolimus over 31 *** and drug loading are adjustable for applications in small and large caliber nerves,and the wrap degrades within 120 days into biocompatible *** released from the nerve wrap promotes axon elongation in vitro and accelerates nerve regeneration and functional recovery in preclinical nerve repair models while off-target systemic drug exposure is reduced by 80%compared with systemic *** its surgical suitability and preclinical efficacy and safety,this system may provide a readily translatable approach to support axonal regeneration and recovery in patients undergoing nerve surgery.

关键词： biodegradable local drug delivery nerve injury nerve regeneration nerve wrap tacrolimus

Prehospital transdermal glyceryl trinitrate for ultra- acute ischaemic stroke: data from the RIGHT- 2 randomised sham- controlled ambulance trial

在线全文

学校读者我要写书评

暂无评论

Stroke & Vascular Neurology 2024年第1期9卷 38-49,I0035-I0046页

作者： jason Philip Appleton Lisa j Woodhouse Craig S anderson Sandeep Ankolekar Lesley Cala Mark Dixon Timothy j England Kailash Krishnan Grant Mair Keith W Muir john Potter Christopher I Price Marc Randall Thompson G Robinson Christine Roffe Else C Sandset jeffrey L Saver Angela Shone Aloysius Niroshan Siriwardena joanna M Wardlaw Nikola Sprigg Philip M Bath Stroke University Hospitals Birmingham NHS Foundation TrustBirminghamUK Institute of Applied HealthResearch University of Birmingham College of Medical and Dental SciencesBirminghamUK Stroke Trials Unit Mental Health and Clinical NeurosciencesUniversity of NottinghamNottinghamUK Faculty of Medicine The George Institute for Global HealthSydneyNew South WalesAustralia The George Institute China at Peking University Health Science Center BeijingChina Neurology Royal Prince Alfred HospitalSydney Health PartnersSydneyNew South WalesAustralia Department of Neurology King's College Hospital NHS Foundation TrustLondonUK Faculty of Health and Medical Sciences University of Western AustraliaCrawleyWestern AustraliaAustralia East Midlands Ambulance Service NHS Trust NottinghamUK Stroke Queen's Medical CentreNottingham University Hospitals NHS TrustNottinghamUK Centre for Clinical Brain Sciences Dementia Research InstituteUniveristy of EdinburghEdinburghUK Institute of Neurology and Psychology University of GlasgowGlasgowUK Bob Champion Research and Education Building University of East AngliaNorwichUK Institute of Neuroscience Newcastle UniversityNewcastle upon TyneUK Department of Neurology Leeds Teaching Hospitals NHS TrustLeedsUK Department of Cardiovascular Sciences and NIHR Leicester Biomedical Research Centre University of LeicesterLeicesterUK Stroke Research in Stoke Institute for Science and Technology in MedicineKeele UniversityStoke-on TrentUK Department of Neurology Oslo University HospitalOsloNorway Research and Development Norwegian Air Ambulance FoundationOsloNorway Department of Neurology and Comprehensive Stroke Center David Geffen School of MedicineUCLALos AngelesCaliforniaUSA Research and Graduate Services University of NottinghamNottinghamUK Community and Health Research Unit University of LincolnLincolnUK

Background The effect of transdermal glyceryl trinitrate(GTN,a nitrovasodilator)on clinical outcome when administered before hospital admission in suspected stroke patients is ***,we assess the safety and efficacy of GTN in the prespecified subgroup of patients who had an ischaemic stroke within the Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2(RIGHT-2).Methods RIGHT-2 was an ambulance-based multicentre sham-controlled blinded-endpoint study with patients randomised within 4hours of *** primary outcome was a shift in scores on the modified Rankin scale(mRS)at day *** outcomes included death;a global analysis(Wei-Lachin test)containing Barthel Index,EuroQol-5D,mRS,telephone interview for cognitive status-modified and Zung depression scale;and neuroimaging-determined‘brain frailty’*** were reported as n(%),mean(SD),median[IQR],adjusted common OR(acOR),mean difference or Mann-Whitney difference(MWD)with 95%*** 597 of 1149(52%)patients had a final diagnosis of ischaemic stroke;age 75(12)years,premorbid mRS>2107(18%),Glasgow Coma Scale 14(2)and time from onset to randomisation 67[45,108]***‘brain frailty’was common:median score 2[2,3](range 0–3).At day 90,GTN did not influence the primary outcome(acOR for increased disability 1.15,95%CI 0.85 to 1.54),death or global analysis(MWD 0.00,95%CI-0.10 to 0.09).In subgroup analyses,there were non-significant interactions suggesting GTN may be associated with more death and dependency in participants randomised within 1hour of symptom onset and in those with more severe *** In patients who had an ischaemic stroke,ultra-acute administration of transdermal GTN in the ambulance did not improve clinical outcomes in a population with more clinical and radiological frailty than seen in previous in-hospital *** IS ALREADY KNOWN ON THIS TOPIC⇒Transdermal glyceryl trinitrate(GTN)was associat-ed with less death and dependency in those w

关键词： Glasgow nitrate random

Polyvinylchloride surface modified with polymer brushes for reduced protein,cell and bacteria attachment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biosurface and Biotribology 2023年第4期9卷 187-198页

作者： Rashed Almousa Dong Xie jiliang Li gregory G.anderson Weldon School of Biomedical Engineering Purdue UniversityWest LafayetteIndianaUSA Department of Medical Equipment Technology College of Applied Medical SciencesMajmaah UniversityAl-MajmaahSaudi Arabia Department of Biomedical Engineering Indiana University-Purdue University at IndianapolisIndianapolisIndianaUSA Department of Biology Purdue School of ScienceIndiana University-Purdue University at IndianapolisIndianapolisIndianaUSA

The objective of this study was to coat negatively charged polymer brushes by a covalent bond onto the surface of polyvinylchloride using a simple conventional surface free radical polymerisation *** coated surfaces were assessed with contact angle,protein adsorption,cell adhesion,and bacterial *** serum albumin and bovine fibrinogen were used for protein adsorption *** fibroblast(NIH-3T3)cells and Pseudomonas aeruginosa were used to assess surface *** show that the surface modified with all the attached polymers exhibited significantly reduced contact angle,protein adsorption,and cell as well as bacterial adhesion among which the negatively charged polymers showed extremely low values in all the *** negatively charged polymer shows its contact angle at 5°as compared to 70°for original *** bovine serum albumin,bovine fibrinogen,3T3 adhesion,and *** adhesion were 93%,84%,92%,and 92%lower than the original PVC,***,the polyvinylchloride surface coated with negatively charged polymer brushes exhibited a hydrogel-like *** results indicate that coating a polyvinylchloride surface with acrylic acids using a simple surface-initiated free radical polymerisation and then converting those to negatively charged salts can be an effective and efficient route for fouling-resistant applications.

关键词： polymer surface

Hydrophilic polymer-coated PVC surface for reduced cell and bacterial adhesions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biosurface and Biotribology 2022年第1期8卷 34-43页

作者： Rashed Almousa Xin Wen Sungsoo Na gregory anderson Dong Xie Weldon School of Biomedical Engineering Purdue UniversityWest LafayetteIndianaUSA Department of Medical Equipment Technology College of Applied Medical ScienceMajmaah UniversityAlmajmaahSaudi Arabia Department of Biomedical Engineering Purdue School of Engineering and TechnologyIndiana University-Purdue University at IndianapolisIndianapolisIndianaUSA Department of Biology Purdue School of ScienceIndiana University-Purdue University at IndianapolisIndianapolisIndianaUSA

Hydrophilic polymers are very useful in biomedical *** this study,biocom-patible polyethylene glycol(PEG)and polyvinylpyrrolidone(PVP)polymers end-capped with succinimidyl groups were either modified or synthesised and attached to poly-vinylchloride *** modified surfaces were evaluated with cell adhesion and bacterial adhesion.3T3 mouse fibroblast cells and three bacteria species were used to evaluate surface adhesion *** showed that the modified surface exhibited significantly reduced 3T3 cell adhesion with a 50%-69%decrease for PEG and a 64%-81%for PVP,as compared to unmodified *** modified surface also showed significantly reduced bacterial attachment with 22%-78%,18%-76%and 20%-75%decrease for PEG and 22%-76%,18%-76%and 20%-73%for PVP to Staphy-lococcus aureus,Escherichia coli and Pseudomonas aeruginosa,respectively,as compared to unmodified *** seems that an appropriate chain length or molecular weight(neither the longest nor the shortest chain length)determines the lowest cell and bacterial adhesion in terms of *** the other hand,a mixture of polymers with different chain lengths exhibited the lowest cell and bacterial adhesion in terms of PVP.

关键词： adhesion bacterial viability polymer polyvinylchloride surface coating